The present invention relates to a new and distinct cultivar of Cotoneaster plant, botanically known as Cotoneaster x suecicus and hereinafter referred to as ‘Emerald Sprite’.
The new Cotoneaster plant is a result of a breeding program directed by the inventor at Oregon State University, Corvallis, Oreg. (US) to develop new cultivars of cotoneasters that are resistant to fire blight caused by the pathogen Erwinia amylovora, are compact, and perform well in nursery production and landscapes.
‘Emerald Sprite’ originated as an open-pollinated seedling collected from Cotoneaster x suecicus ‘Coral Beauty’ (seed parent, unpatented) during 2011 that was pollinated by an unknown pollen parent. It was originally accessioned and evaluated as H2011-02-001. ‘Emerald Sprite’ was grown in containers during 2012 for observation and selected for propagation in 2013. It was propagated by stem cuttings that rooted easily with hormone treatment under mist in a glasshouse located on Oregon State University's main campus at 2801 SW Campus Way, Corvallis, Oreg. Clones produced from serial asexual propagation have demonstrated the stability of its traits from 2013 through 2018. The original plant was left outside unprotected in a #3 container during winter 2013-14 and was killed during temperatures that reached 0° F. Replicates produced from stem cuttings were included in a glasshouse study to evaluate fire blight resistance of hybrids and parents during 2014. Plants were inoculated on Apr. 28, 2014 with a virulent strain (Ea153) of Erwinia amylovora by bisecting the two youngest leaves on vigorously growing shoots according to Rothleutner et al. (2014). None of the plants of this accession exhibited disease symptoms (0% shoot infection). ‘Coral Beauty’ had 11.1% mean shoot infection during that evaluation.